Hello Dayfan ~ I find your accomplishment inspiring to say the least. I began learning antique radio repair when I was 12 (1974), and several years ago, built the 1954 Moog theremin, as you did in the 70s-- see April 2005 photo archives on this site: http://www.thereminworld.com/gal-pom.asp Before I acquired my RCA last year, I was gearing up to attempt an RCA copy, based on the Harrison data and the RCA red book, but was stumped by the unknown data. Congratulations on deducing what needed to be known. I'd love to know more about this. In the mean time, I can help you with the tone quality of the instrument you built. I've been acquiring information on this, as I've worked on improving the voicing of my RCA. The methods are primarily concerned with tubes, and do not require altering the circuit except (optionally) for the grid connection to the 24A. I would be happy to compare notes with you if you would like to get in touch. Thanks again for a marvelous and inspiring article!